The Technobox 4936 Fan Assembly is an option that can be installed on a number of Technobox PMC and XMC Adapters (e.g., P/Ns 4733, 4749, 4821, 4822, 4823, 4930, 5012, 5243, 5933, 5934, 5935, and 5944) to augment cooling. Airflow is upward.